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For the ones that are switching or already have switched to a digital trunking system: How are you going to to page your volunteers? From my understanding there are no P25, DMR or Nexedge pagers. Are all the volunteers getting a radio or are you going to keep both infrastructures and simulcast?
The next question would be then if we should keep the analog system for backup even if they came out with a P25 pager.
What are your plans?
My county switched to a 800MHz trunked system several years ago. In order to maintain the paging capability, they have to simulcast the main channel on the pager frequencies. I've not heard of anybody that has plans to make a pager that works on the 800MHz systems, so we'll be using this system for a while.
The very nature of trunked radio makes paging as we know it impossible - on the trunked system itself. There are ways to handle the task.
I believe you'll find that any agency using trunking and paging has a separate frequency used specifically for paging. Sometimes that channel is linked directly to the dispatch channel so you can hear both the dispatcher and field units, sometimes it only carries the dispatcher. I'd imagine there are those who run it completely separately.
If you have an existing analog frequency and it's working for you, keep it.
I'm not so sure you'd want to pay the price for a trunking capable pager. Even your basic digital trunking scanner comes in at better than twice the cost of an analog scanner. Add the usual fire service mark-up and you could be talking $1,000 a pager...
And, while progress is being made, digital systems don't always do real well with paging tones.
Given the push for narrowbanding, I wouldn't be surprised to see a move to non-commercial based alpha-numeric systems, operated completely by the dispatch agencies. My county is already providing texts to cell phones, so I know it would be a short jump to go to A/N paging.
The problem with text messages via cell phone is that sometimes it gets there quickly and sometimes it can take 5-10 mins. I have received the text before the audio over the 800 freq. and also have had a several min. delay.
If your department already has a system, like a minitor pager, stay with that. They will have to keep the frequency that works the pagers and simulcast the trunked frequencies over onto the one for the pagers.
It is done everyday in many places.
Yep - I've had it beat the page as well as come in minutes later - or not at all.Quote:
Originally Posted by Fitguy51
Not recommended as a primary paging solution, but can be handy if you need to look up the address again.
I also don't recommend using a commercial A/N system - install your own...
My department is part of a county dispatch. We have had a trunked system for many years. There is a main firs dispatch channel, where the tones go out. However, for the guys that still have voice pagers, they are tuned to the low band county repeater. Other than that, we use alphanumeric pagers, which only have a 1-2 second delay from the tones themselves. Also, everyone in the department receives text messages from the county dispatch.
All that being said, each method has its flaws. For example, the alphanumeric pagers sometimes receive jumbled pages, or will not even receive the page. This is a very rare occurrence. As for the text messages, they usually come in 1-2 minutes after the tones drop. I think the text message is the least effective. The voice pagers seem the best and most reliable.
All in all, there really isn't a way to page on a trunked system. A repeater seems to be the most effective, at least where I come from.
Thanks for the answers guys. Do I understand you right? You think its impossible to make a P25 pager? My knowledge is limited but I do know that it wouldnt work with tones. Wouldnt the P25 pager simply listen to the control channel and switch to the lets say "alert talk group" when being alerted? I bet such a pager would cost just as much as a P25 radio.
I believe another plus to keep your analog system is that when the digital trunking system goes down you at least still have your analog frequency to communicate and alert.
The number of control channels depends on the size of the system. Most of the 800MHz digital system that surround me, including the one at work, have four control channels. Then when you talk about the regional system, each of the three jurisdictions on the regional system have four control channels, making a total of 12 that could be used at any time by any jurisdiction. So not only would the pager have to be capable of hearing DTMF or 2-tone sequential paging, it would also have to monitor multiple CC's at the same time.
The cost of a digitally-capable pager alone outweighs the benefit of mass-producing something like that, unfortunately. Therefore, continuing to page via VHF or UHF continues to be the norm for most places.
As for using the VHF or UHF channel for back-up communications, you'd have to make sure that all of the old VHF or UHF radios weren't removed from the vehicles. Most places that go 800MHz or 700MHz keep the old frequency for paging only, and having a 2-way conversation on that same frequency might not even be possible.
The P25 system I ran rotated control channels to even out "wear and tear" on the system. There were three sites - one had 11 possible control channels, one had 5, and one had 3. Which one are we supposed to listen to?Quote:
Originally Posted by koechler
As you say - the best thing is a separate paging channel, be it analog or alphanumeric text.
Could a P25 paging system be designed? Sure, I think so.. but it would be expensive.
A talkgroup could be set up for all paging, and then the tones continue to differentiate units/stations/departments, whatever. To avoid the tones a talkgroup could be set up per-unit/station/department. Either way the pager monitors a talkgroup for activity.
Multiple talk groups on a pager would be a problem.. not sure if radios/pagers could monitor multiple talk groups w/out missing something. Also, the volume of talk-groups could become a problem.. I'm not sure how the number of talkgroups scale versus the complexity of the P25 setup.
Either way, I don't think the cost of the P25 pagers would be less than maintaining two seperate systems.. especially if the analog paging system is already established. That' what we do here, analog paging and digital trunking mobiles.
I hate it when I wear a hole in my electromagnetic spectrum.. :DQuote:
Originally Posted by tree68
Yeah - those spurious transmissions are a real pain in the keister.Quote:
Originally Posted by voyager9
Our department had an offer to install a repeater and base station to our department with them giving us the repeater to switch the department to digital / Analog. To receive and talk to 911 when we are toned we would still have to use the analog system. Also the radios that they want us to purchase is a Hytera Digital/ Analog radio. He stated that everything was compatible and wouldnt have any problems, but what i see is if we go the repeater route there is $1000 for a 10 year license and we dont know how the coverage would be. We are a very rural area, (a mountain splitting our coverage in the middle). Does anyone know if this system would be a good idea for our department?? He stated that we didnt have to have the repeater but there would be minimal digital coverage. Also, the digital would only be used for inner-department activities (Text Messages, etc.) Also we would be able to keep track if any of our members have an open mic. Could anyone give me some input??
Coverage??
Radio Durability??
Benefit or hurt us??
Thanks!!!!!!!!!!!!!!
See the replies in the other thread.
There is a company down south that sells a low cost system that connects digital and VHF radio systems together. www.wcdielectronics.com
There is a company down south that sells a low cost system that connects digital and VHF radio systems together. It pages by sending page-tones used by the older radios. www.wcdielectronics.com